Automatic overhead door opener



y 15, 7 J. R. WIEGAND 3,319,696

AUTOMATIC OVERHEAD DOOR OPENER Filed June 4, 1965 3 Sheets-Sheet 1 106 lLIN/l wrrcn John 7?. H11 egand BY W47 ATTURNEYS'.

INVENTOR y 16, 1967 J. R. WIEGAND 3,319,696

AUTOMATIC OVERHEAD DOOR OPENER Filed June 4, 1965 3 Sheets-Sheet 2 ATTU.5.

AUTOMATIC OVERHEAD DOOR OPENER Filed June 4, 1965 3 Sheets-Sheet I t I52 INVENTOR J0/7/7 R Mega/7d BY 5 ifiawzas.

United States Patent Ofitice 3,319,696 AUTOMATIC OVERHEAD DOOR OPENERJohn R. Wiegand, Valley Stream, N.Y., assiguor to Wiegand ElectronicsCo., Inc, County of Union, N.J., a corporation of New .lersey Filed June4, 1965, Ser. No. 461,366 9 Claims. (Cl. 160188) It is one object of theinvention to provide a door opener adapted for installation on aconventional door mounted in a doorway having rails at sides of thedoorway for guiding the door to open to an open overhead position.

Another object is to provide a door opener as described with a winchactuated by a control circuit operated by a pushbutton switch foropening and closing the door.

Still another object is to provide a door opener for an overhead doorwith a spring loaded drawbar arranged to prevent opening the doormanually.

Another object is to provide a control circuit for a door opener with alimit switch actuated by a winch gear at upper and lower limits oftravel of the door, and with a pushbutton operated latch switch foractuating and reversing a motor which drives a Winch.

For further comprehension of the invention, and of the objects andadvantages thereof, reference will be had to the following descriptionand accompanying drawings and to the appended claims in which thevarious novel features of the invention are more particularly set forth.

In the accompanying drawings forming a material part of this disclosure:

FIG. 1 is a perspective front view of a garage door in closed positionwith a door opener embodying the invention installed thereon.

FIG. 2 is an enlarged vertical sectional view taken on line 22 of FIG.1, parts being broken away.

FIG. 3 is a further enlarged fragmentary vertical sectional view takenon line 33 of FIG. 2, showing parts of the mechanism of the door opener.

FIG. 4 is a still further enlarged view partially in section of portionsof the mechanism of FIG. 3, shown in one operating position.

FIG. 5 is a view similar to a portion of FIG. 4 showing parts of themechanism in dilferent operating position.

FIG. 6 is an exploded sectional view of parts of the mechanism of FIGS.4 and 5.

FIG. 7 is a diagram of the electrical control system of the door opener.

Referring first to FIGS. 1 and 2 there is shown the door opener 10including a flexible cable 12 having a loop 14 at its lower end securedto a bracket 16 mounted on the outer side of lowermost section 17 of agarage door 20. The bracket is located near the bottom of section 17.The door 20 has sections 17, 18, 19 secured together by hinges 22 at therear side of the door. Above the door is lintel 24 of the front wall 25of a garage or other building 26 provided with rectangular door opening28. Just above the door on the outside of the lintel is a lamp 30 whichlights during operation of the door opener as described below. At oneside of the door opening on wall 25 is a key operated lockswitch 32,used to actuate the mechanism of the door opener. At opposite sides ofthe door opening and at lateral edges of the door are curved channelshaped rails 33 of conventional type on which the door 20 can be drawnup. In rails 33 are engaged rollers 34. The rollers are supported byshafts 35 mounted in brackets 35a on the rear side of door section 19.

The door opener 10 further includes a housing 36 in which is areversible motor 37 best shown in FIG. 3. Housing 36 is shown in FIG. 2mounted on a bracket plate 38 at the rear side of the lintel 24. Bracketplate 3,319,696 Patented May 16, 1967 38 is mounted by bolts 39. Anoutwardly or rearwardly extending angle bar 40 is mounted on plate 38adjacent to housing 36.

Just below angle bar 40 is a bracket 42 on lintel 24 carrying an idlerpulley 44. Below pulley 44 and bracket 42 on the rear side of doorsection 19 is an angle bracket 46 held by bolts 47. On rearwardlyextending arm 49 of the bracket 46 is a rivet or pin 50 pivotallysupporting a draw bar 52 in a vertical position. The bar 52 carriesidler pulley 54 at its upper end. At the lower end of bar 52 is arearwardly extending arm 56. At the outer end of arm 56 is attached thelower end of a spring 60. The upper end of the spring is engaged withloop 62 at the upper end of cable 12. Another spring 64 is attached atits upper end to the outer end of bracket arm 56. The lower end ofspring 64 is attached to an arm of a small angle bracket 65 mounted nearthe lower end of door section 19.

Referring now to FIGS. 2 and 3, there is shown a winch pulley 66 havinga hub 67 provided with a spur gear 68. The pulley, hub and gear are allforming an integral unit secured to drive shaft 70' of a gear reductionunit 71 in the housing of motor 37 to which the unit 71 is coupled inconventional manner.

The gear 68 is meshed with a splined gear 72 loosely mounted on one endof a nonrotatable shaft 74 so as to be rotatable independently of theshaft. The shaft 74 is pivotally engaged by a pin 76 at its other end.The shaft extends through a stationary bracket 78 having a U- shapedinsert 77. In this insert is a spring 79 which bears on the bight ofinsert 77 and on the side of the shaft to bias it into a horizontalposition. The two turns of cable 12 around winch 66 constitutes a slipclutch arrangement. The splined gear 72 has an externally threaded hub73 meshed with internal thread 81 of cup gear 83 which has a ballbearing at the other end to have this gear roll freely, with the bearingfastened onto the shaft 74; see FIGS. 4, 5 and 6. The cup gear has asmooth outer cylindrical wall 83. Between wall 83" and the groovedperiphery of winch 66 passes the cable 12. The cable is wound twicefully around the winch to define a double turn 84.

It will be noted in FIG. 2 that the cable 12 extends upwardly frombracket 16 at the front of the door, then enters the space S between thetop of the door and bottom of the lintel 24. The cable is entrained atthe rear of pulley 44 and then passes upwardly to form the double turn84 around winch 66. Then the cable extends rearwardly over pulley 54,and down to join the upper end of spring 60 at loop 62.

In housing 36 on plate 38 is mounted bracket 78 in which is a limitswitch 86. This switch has an operating arm 87 pivotally mounted onbracket '87 at its upper end to actuate the finger 88 of the switch. Atits lower end the arm 87 carries a rotatable roller 89 which bearsagainst one end 72' of splined gear 72. The roller 89 contacts the gear72 even in its extreme right position shown in FIG. 3. A coil spring 90has one end engaged in a hole 91 in shaft 74, and its other end bears onthe end 72' of gear 72.

In the housing 36 are also mounted transformer 94 and relay 96 formingparts of the electrical control circuit 100 of the door opener. Thecircuit is shown schematically in FIG. 7 to which reference is now made.

The circuit includes :a power supply cable 102 from which power can bedrawn from a conventional power supply source. One wire 103 is grounded.The other wire 104 is connected to contacts 105, 106 of limit switch 86.The limit switch is a double-pole double-throw switch. In the positionshown in FIG. 7, one pole 108 contacts fixed contacts 105, 107 and isopen with respect to fixed contacts 106, 109. The other pole 110 isshown closed with fixed contacts 111, 112 and is open with respect tocontacts 113, 114.

Relay 96 is a latch relay having a coil 116 connected in series withnormally open pushbutton switch contacts 118 of the manually operablekey switch 32 and secondary winding 119 of stepdown transformer 94. Theprimary winding 120 of the transformer is connected to power supplywires 102, 103. Relay 96 has two movable contacts 122, 124. Contact 122moves between fixed contacts 123, 125. Contact 124 moves betweencontacts 1'26, 127. Lamp 30 is connected between ground and switchcontact 109.

Contact 107 is connected to contact 127. Contacts 124 are connected toarmature winding 130 of motor 37. The armature Winding in turn isconnected to both contacts 123 and 112. The field winding 132 of themotor is connected to contacts 111, 114 and contact 122. Contact 113 isgrounded as is contact 125.

In operation of the door opener including control circuit 100, supposethe door 20 is closed as shown in FIGS. 1 and 2. The cable 12 will betaut which will hold the draw bar 52 vertical since the cable isentrained over pulley 54 as shown in FIG. 2. The springs 60 and 64 willboth be tensioned. In this position of the draw bar, it will not bepossible to open the door manually by lifting it, because the draw barwill not be able to pass the rearwardly extending horizontal arm ofangle bar 40.

If it is now desired to open the door automatically a suitable key willbe inserted into the key switch 32 and turned to close the contactsmomentarily. This will energize relay 96 and contacts 122, 124 willshift to the right as viewed in FIG. 7 to close with contacts 125 and127 respectively. This will apply power to the armature and field of themotor which will start. The shaft 70 will turn so as to pull up thecable 12. As the part of the cable extending from turn 84 to spring 60lengthens the spring contracts permitting spring 64 to contract and drawbar 52 swings outwardly or rearwardly as indicated by dotted lines inFIG. 2. The motor continues to operate and the door is drawn up alongrails 33 to an overhead position.

When the cable 12 reaches the limit of its upward travel with the door20 in an overhead horizontal position winch 66 slips in the cable turn84 while the shaft 70 with gear 68 continues to rotate. While the cable12 was being drawn up the cup gear 83 rotates along with gear 72. Bothgears 72 and 83 rotate freely on shaft 74. When the cable stops moving,the stationary cable frictionally engages the wall 83 of cup gear 83 sothat this gear remains stationary. The continuing rotation of gear 68now rotates gear 72 along which slides axially to the left as shown inFIGS. 35 while its splines still retain engagement with gear 68. As gear72 moves to the left it moves roller 89 and switch arm 87 so that thelimit switch is thrown from the right position shown in FIG. 7 to itsalternate left position. Pole 108 then closes with contacts 106, 109 andpole 110 closes with contacts 113, 114. In this situation, the powersupply to the field and armature windings at contacts 105, 107, 108 isbroken and the motor stops. If the motor should tend to overrun, theteeth of gear 68 will slip with respect to the splines of gear 72 asshaft 74 will move laterally in the slip clutch arrangement previouslymentioned. When the motor stops, gear 72 remains in its left position.The motor will stop, leaving the door in fully open position. When themotor stops, with the door open, the lamp will be lighted through closedcontacts 106, 108, 109.

When it is desired to close the door the key switch 32 can again beoperated momentarily. The relay 96 will again be actuated to movecontacts 122, 124 back to the left position shown in FIG. 7. The motorwill now be energized through relay contacts 106, 108, 109 and will bereversed in its direction of rotation. This will permit the cable 12 tomove upwardly past pulley 54 around winch 66 and down past pulley 44.The motor will continue this drive while the door itself descends due toits own weight. The slowly moving cable 12 will limit the speed ofdescent of the door. The lamp 30 will remain lighted.

While the door is descending gear 72 remains in its left position andarm 87 of switch 86 is held in its position since cup gear 83 turns withgear 72. When the door reaches the bottom of the doorway opening 28 andis stopped at the ground G the cable 12 will again become taut and thedrawbar will again assume a fully vertical position to tension springs60 and 64. When the cable 12 stops moving around winch 66, the winch 66which is now turning in reverse direction will slip in the cable turn84. Then gear 83 will be held frictionally by the stopped cable and gear72 will be turned by gear 68 to reengage fully in gear 83. This willpermit switch arm 87 to swing to the right. The switch poles 108, willthen be restored to the position shown in FIG. 7. The light of lamp 30will then go out, and the motor circuit will open.

There has thus been provided a door opener which operates automaticallyfor opening and closing an overhead door. In operation, the motor 37drives the winch 66, around which are two turns of a flexible cable 12,the ends of said cable being fastened to the outside bottom of door 20then up and twice around the winch 66 then over a small pulley on top ofthe drawbar and then onto the spring 60. When the door hits anobstruction going up or down or reaches its upper or lower limit, thecable 12 will slide on the winch 66, since the spring 60 is not holdingthe cable 12 too tight. When this cable 12 slips on the winch, the idlerpulley will stop also because it is riding on top of the two turns ofcable which stopped moving. When this happens, the motor is stilldriving the winch and the gear 68 is driving the gear 72 with its thread73, since the idler pulley is standing still and the gear is rotatingout of its threaded housing, the lever 87 will move over to activate thelimit switch 86 and stop the motor.

When the latching relay 96 is activated, the motor 37 is started inopposite rotation. The diameter relation is such that the gear 72 staysout of its thread housing until another obstruction stops the cableagain whereupon the idler stops with the cable again and the gear 72rotates its thread into the idler stopping the motor again. Instead of akey operated switch 32 a simple pushbutton switch can be mounted on thewall 25. Alternatively the pushbutton or key operated switch can bemounted on a post (not shown) spaced forwardly from door 20. The controlcircuit can have switch 32 arranged for operation by remote radiocontrol.

While I have illustrated and described the preferred embodiments of myinvention, it is to be understood that I do not limit myself to theprecise constructions herein disclosed and that various changes andmodifications may be made within the scope of the invention as definedin the appended claims.

What is claimed is:

1. A door opener for a door mounted between curved guide rails at adoorway and movable between a lowered closed position and an overheadopen position, comprising a cable attachable at one end to said doornear its bottom end, a winch assembly mountable on a lintel over saiddoorway, said winch assembly including a winch pulley, said cable beingentrained on said pulley for pulling the door upwardly on said rails andfor paying out the cable as the door descends, -a reversible motor insaid assembly operatively connected to and driving said pulley, a coilspring connected at one end to the other end of the cable, a bracketmountable on said door, a vertical drawbar pivotally mounted on saidbracket, an idler pulley carried at the upper end of said drawbar andguiding an end part of said cable beyond said winch pulley, an armextending outwardly of the lower end of said drawbar, the other end ofsaid coil spring being connected to said arm for holding said end partof the cable in a taut position when the door is lowered, whereby saiddrawbar is held in a vertical position, and an angle bar mountable oversaid drawbar to prevent passage of said drawbar and manual opening ofsaid door.

2. A door opener for a door mounted between curved guide rails at adoorway and movable between a lowered closed position and an overheadopen position, comprising a cable attachable at one end to said doornear its bottorn end, a winch assembly mountable on a lintel over saiddoorway, said winch assembly including a winch pulley, said cable beingentrained on said pulley for pulling the door upwardly on said rails andfor paying out the cable as the door descends, a reversible motor insaid assembly operatively connected to and driving said pulley, a coilspring connected at one end to the other end of the cable, a bracketmountable on said door, a vertical drawbar pivotally mounted on saidbracket, an idler pulley carried at the upper end of said drawbar andguiding an end part of said cable beyond said winch pulley, an armextending outwardly of the lower end of said drawbar, the other end ofsaid coil spring being connected to said arm for holding said end partof the cable in a taut position when the door is lowered, whereby saiddrawbar is held in a vertical position, and an angle bar mountable oversaid drawbar to prevent passage of said drawbar and manual opening ofsaid door, another bracket mountable on said door below the first namedbracket, and another spring connected between the drawbar arm and saidother bracket for pivoting said drawbar to clear said angle bar when thecable starts to elevate the door and the first named spring contracts assaid end part of the cable lengthens.

3. A door opener for a door mounted between curved guide rails at adoorway and movable between a lowered closed position and an overheadopen position, comprising a cable attachable at one end to said doornear its bottom end, a winch assembly mountable on a lintel over saiddoorway, said winch assembly including a winch pulley, said cable beingentrained on said pulley for pulling the door upwardly on said rails andfor paying out the cable as the door descends, a reversible motor insaid assembly operatively connected to and driving said pulley, ahorizontal nonrotatable shaft, an internally threaded cup gear freelyrotatable on one end of said shaft, a splined gear having an externalthreaded hub freely rotatable on said shaft and engaged in said cupgear, said cup gear being located adjacent said winch pulley forengaging a turn of said cable on said winch pulley to turn therewith,and a spur gear integral with said winch pulley for turning therewith,said spur gear being meshed with said splined gear to turn the samealone when the cup gear is held stationary by a stationary turn of thecable on the winch pulley so that the splined gear moves axially withrespect to the cup gear.

4. A door opener for a door mounted between curved guide rails at adoorway and movable between a lowered closed position and an overheadopen position, comprising a cable attachable at one end to said doornear its bottom end, a winch assembly mountable on a lintel over saiddoorway, said winch assembly including a winch pulley, said cable beingentrained on said pulley for pulling the door upwardly on said rails andfor paying out the cable as the door descends, a reversible motor insaid assembly operatively connected to and driving said pulley, anelectric power supply for energizing the motor, horizontal nonrotatableshaft, an internally threaded cupgear freely rotatable on one end ofsaid shaft, a splined gear having an external threaded hub freelyrotatable on said shaft and engaged in said cup gear, said cup gearbeing located adjacent said winch pulley for engaging a turn of saidcable on said winch pulley to turn therewith, a spur gear integral withsaid winch pulley for turning therewith, said spur gear being meshedwith said splined gear to turn the same alone when the cup gear is heldstationary by a stationary turn of the cable on the winch pulley so thatthe splined gear moves axially with respect to the cup gear, a manuallyoperable normally open switch, and a two-position latching relayconnected in circuit with said switch, power supply and motor forstarting the motor in either of two directions of rotation when theswitch is closed while the door is in closed and open positionsrespectively.

5. A door opener for a door mounted between curved guide rails at adoorway and movable between a lowered closed position and an overheadopen position, comprising a cable attachable at one end to said doornear its bottom end, a winch assembly mountable on a lintel over saiddoorway, said winch assembly including a winch pulley, said cable beingentrained on said pulley for pulling the door upwardly on said rails andfor paying out the cable as the door descends, a reversible motor insaid assembly operatively connected to and driving said pulley, anelectric power supply for energizing the motor, a horizontalnonrotatable shaft, an internally threaded cup gear freely rotatable onone end of said shaft, a splined gear having an external threaded hubfreely rotatable on said shaft and engaged in said cup gear, said cupgear being located adjacent said winch pulley for engaging a turn ofsaid cable on said winch pulley to turn therewith, a spur gear integralwith said winch pulley for turning therewith, said spur gear beingmeshed with said splined gear to turn the same alone when the cup gearis held stationary by a stationary turn of the cable on the winch pulleyso that the splined gear moves axially with respect to the cup gear, amanually operable normally open switch, a two-position latching relayconnected in circuit with said switch, power supply and motor forstarting the motor in either of two directions of rotation when theswitch is closed while the door is in closed and open positionsrespectively, and a twoposition limit switch having a pivotable armlocated for lateral movement by said splined gear when the splined gearmoves axially, said limit switch being connected in circuit with saidreversible motor and power supply for interrupting the supply of powerto the motor for stopping the motor at each end of travel of said doorat fully closed and fully open positions thereof.

6. A door opener for a door mounted between curved guide rails at adoorway and movable between a lowered closed position and an overheadopen position, comprising a cable attachable at one end to said doornear its bottom end, a winch assembly mountable on a lintel over saiddoorway, said winch assembly including a winch pulley, said cable beingentrained on said pulley for pulling the door upwardly on said rails andfor paying out the cable as the door descends, a reversible motor insaid assembly operatively connected to and driving said pulley, a coilspring connected at one end to the other end of the cable, a bracketmountable on said door, a vertical drawbar pivotally mounted on saidbracket, an idler pulley carried at the upper end of said drawbar andguiding an end part of said cable beyond said winch pulley, an armextending outwardly of the lower end of said drawbar, the other end ofsaid coil spring being connected to said arm for holding said end partof the cable in a taut position when the door is lowered, whereby saiddrawbar is held in a vertical position, and an angle bar mountable oversaid drawbar to prevent passage of said drawbar and manual opening ofsaid door, another bracket mountable on said door below the first namedbracket and another spring connected between the drawbar arm and saidother bracket for pivoting said drawbar to clear said angle bar when thecable starts to elevate the door and the first named spring contracts assaid end part of the cable lengthens, a horizontal nonrotatable shaft,an internally threaded cup gear freely rotatable on one end of saidshaft, a splined gear having an external threaded hub freely rotatableon said shaft and engaged in said cup gear, said cup gear being locatedadjacent said winch pulley for engaging a turn of said cable on saidwinch pulley to turn therewith, and a spur gear integral with said winchpulley for turning there- 7 with, said spur gear being meshed with saidsplined gear to turn the same alone when the cup gear is held stationaryby a stationary turn of the cable on the winch pulley so that thesplined gear moves axially with respect to the cup gear.

7. A door opener for a door mounted between curved guide rails at adoorway and movable between a lowered closed position and an overheadopen position, comprising a cable attachable at one end to said doornear its bottom end, a winch assembly mountable on a lintel over saiddoorway, said winch assembly including a winch pulley, said cable beingentrained on said pulley for pulling the door upwardly on said rails andfor paying out the cable as the door descends, a reversible motor insaid assembly operatively connected to and driving said pulley, a coilspring connected at one end to the other end of the cable, a bracketmountable on said door, a vertical drawbar pivotally mounted on saidbracket, an idler pulley carried at the upper end of said drawbar andguiding an end part of said cable beyond said winch pulley, an armextending outwardly of the lower end of said drawbar, the other end ofsaid coil spring being connected to said arm for holding said end partof the cable in a taut position when the door is lowered, whereby saiddrawbar is held in a vertical position, and an angle bar mountable oversaid drawbar to prevent passage of said drawbar and manual opening ofsaid door, another bracket mountable on said door below the first namedbracket, and another spring connected between the drawbar arm and saidother bracket for pivoting said drawbar to clear said angle bar when thecable starts to elevate the door and the first named spring contracts assaid end part of the cable lengthens, a horizontal nonrotatable shaft,an internally threaded cup gear freely rotatable on one end of saidshaft a splined gear having an external threaded hub freely rotatable onsaid shaft and en gaged in said cup gear, said cup gear being locatedadjacent said winch pulley for engaging a turn of said cable on saidwinch pulley to turn therewith, and a spur gear integral with said winchpulley for turning therewith, said spur gear being meshed with saidsplined gear to turn the same alone when the cup gear is held stationaryby a stationary turn of the cable on the winch pulley so that thesplined gear moves axially with respect to the cup gear, a two-positionlimit switch having a pivotable arm located for lateral movement by saidsplined gear when the splined gear moves axially, and an electric powersupply for energizing the motor, said limit switch being connected incircuit with said reversible motor and power supply for interrupting thesupply of power to the motor for stopping the motor at each end oftravel of said door. at fully closed and fully open positions thereof.

8. A door opener for a door mounted between curved guide rails at adoorway and movable between a lowered closed position and an overheadopen position, comprising a cable attachable at one end to said doornear its bottom end, a winch assembly mountable on a lintel over saiddoorway, said winch assembly including a winch pulley, said cable beingentrained on said pulley for pulling the door upwardly on said rails andfor paying out the cable as the door descends, a reversible motor insaid assembly operatively connected to and driving said pulley, a coilspring connected at one end to the other end of the cable, a bracketmountable on said door, a vertical drawbar pivotally mounted on saidbracket, an idler pulley carried at the upper end of said drawbar andguiding an end part of said cable beyond said winch pulley, an armextending outwardly of the lower end of said drawbar, the other end ofsaid coil spring being connected to said arm for holding said end partof the cable in a taut position when the door is lowered, whereby saiddrawbar is held in a vertical position, and an angle bar mountable oversaid drawbar to prevent passage of said drawbar and manual opening ofsaid door, a horizontal nonrotatable shaft, an internally threaded cupgear freely rotatable on one end of said shaft, a splined gear having anexternal threaded hub freely rotatable on said shaft and engaged in saidcup gear, said cup gear being located adjacent said winch pulley forengaging a turn of said cable on said winch pulley to turn therewith,and a spur gear integral with said winch pulley for turning therewith,said spur gear being meshed with said splined gear to turn the samealone when the cup gear is held stationary by a stationary turn of thecable on the winch pulley so that the splined gear moves axially withrespect to the cup gear.

9. A door opener for a door mounted between curved guide rails at adoorway and movable between a lowered closed position and an overheadopen position, comprising a cable attachable at one end to said doornear its bottom end, a winch assembly mountable on a lintel over saiddoorway, said winch assembly including a winch pulley, said cable beingentrained on said pulley for pulling the door upwardly on said rails andfor paying out the cable as the door descends, a reversible motor insaid assembly operatively connected to and driving said pulley, ahorizontal nonrotatable shaft, an internally threaded cup gear freelyrotatable on one end of said shaft, a splined gear having an externalthreaded hub freely rotatable on said shaft and engaged in said cupgear, said cup gear being located adjacent said winch pulley forengaging a turn of said cable on said winch pulley to turn therewith,and a spur gear integral with said winch pulley for turning therewith,said spur gear being meshed with said splined gear to turn the samealone when the cup gear is held stationary by a stationary turn of thecable on the winch pulley so that the splined gear moves axially withrespect to the cup gear, means pivotally mounting said nonrotatableshaft adjacent to said motor, and spring means bearing laterally on saidshaft, whereby said shaft moves laterally in a slip clutch arrangementwhen the motor overdrives said spur gear after splined gear moves toeach of two extreme axial positions with respect to said cup gear.

References Cited by the Examiner UNITED STATES PATENTS 2,923,541 2/1960Gessell 189 2,936,830 5/1960 Mosher 160188 2,954,224 9/ 1960 Schneideret al 42-28 X 3,207,502 9/1965 Houk 160-188 X DAVID J. WILLIAMOWSKY,Primary Examiner.

HARRISON R. MOSELEY, Examiner.

I. K. BELL, Assistant Examiner.

1. A DOOR OPENER FOR A DOOR MOUNTED BETWEEN CURVED GUIDE RAILS AT ADOORWAY AND MOVABLE BETWEEN A LOWERED CLOSED POSITION AND AN OVERHEADOPEN POSITION, COMPRISING A CABLE ATTACHABLE AT ONE END TO SAID DOORNEAR ITS BOTTOM END, A WINCH ASSEMBLY MOUNTABLE ON A LINTEL OVER SAIDDOORWAY, SAID WINCH ASSEMBLY INCLUDING A WINCH PULLEY, SAID CABLE BEINGENTRAINED ON SAID PULLEY FOR PULLING THE DOOR UPWARDLY ON SAID RAILS ANDFOR PAYING OUT THE CABLE AS THE DOOR DECENDS, A REVERSIBLE MOTOR IN SAIDASSEMBLY OPERATIVELY CONNECTED TO AND DRIVING SAID PULLEY, A COIL SPRINGCONNECTED AT ONE END TO THE OTHER END OF THE CABLE, A BRACKET MOUNTABLEON SAID DOOR, A VERTICAL DRAWBAR PIVOTALLY MOUNTED ON SAID BRACKET, ANIDLER PULLEY CARRIED AT THE UPPER END OF SAID DRAWBAR AND GUIDING AN ENDPART OF SAID CABLE BEYOND SAID WINCH PULLEY, AN ARM EXTENDING OUTWARDLYOF THE LOWER END OF SAID DRAWBAR, THE OTHER END OF SAID COIL SPRINGBEING CONNECTED TO SAID ARM FOR HOLDING SAID END PART OF THE CABLE IN ATAUT POSITION WHEN THE DOOR IS LOWERED, WHEREBY SAID DRAWBAR IS HELD INA VERTICAL POSITION, AND AN ANGLE BAR MOUNTABLE OVER SAID DRAWBAR TOPREVENT PASSAGE OF SAID DRAWBAR AND MANUAL OPENING OF SAID DOOR.